When articles or garments are laundered, a major problem associated during the course of laundering operations involves the possibility of colored items to discharge dye into the wash solution. The discharged extraneous dye, which may also be referred as “fugitive dye,” is then deposited or associated onto other articles or garments present in the wash cycle and thereby alters the color of garments. This dye carry-over phenomenon is referred to as “dye transfer”. The discoloration of articles or garments results in unsatisfactory and faded appearance and after many times are rendered inappropriate for further use. Another similar problem involves the premature fading of articles or garments within the wash solution as a result of undesirable dye discharge. One way of addressing the problem of extraneous dye deposition onto articles or garments within the wash solution is to form a complexation and/or absorption of fugitive extraneous dyes before they can be deposited onto articles or garments.
U.S. Pat. Nos. 5,451,337 and 5,474,576 disclose an approach to bleach the dyes that are released into the washing solution before they have a chance to transfer to other articles and/or garments. The use of bleaching agents has the undesirable effect of bleaching not only the fugitive dyes, but also bleaching the dyes still attached to the articles and/or garments, resulting in fading or color change of the dyed articles and/or garments. The oxidizing agents can also interfere with laundry detergent components, making the detergents less effective.
U.S. Pat. No. 4,380,453 discloses other techniques for dealing with extraneous dyes in wash liquors involving the use of specific quaternized dye scavengers that are supported on cellulosic substrates. U.S. Pat. No. 4,494,264 discloses a “filtering envelope approach” to address this problem and wherein the dye-generating articles or garments are physically separated from non dye-generating garments.
U.S. Pat. No. 5,698,476 discloses a system for removing extraneous, random free-flowing dyes from laundry washing applications which comprises a novel unitary dosing laundry article that can freely circulate among items being laundered. The laundry article further comprises a dye absorber and a dye transfer inhibitor which are introduced into wash liquor via a support matrix. The dye absorber maintains a relational association with the support matrix in the wash liquor, whereas the dye transfer inhibitor is delivered up from the support matrix to the wash liquor and may be evenly distributed throughout the wash liquor.
U.S. Pat. No. 4,954,292 assigned to Hull et al. discloses the use of polyvinyl pyrrolidone to prevent redeposition of soils or dyestuffs when used in a laundry detergent in combination with an anionic surfactant and a specific nonionic with an HLB of 10.5 or less.
Several approaches to address the problem of fugitive extraneous dyes in a laundering cycle involve the use of dye transfer inhibitors added directly to a wash liquor of the washing machine either as a laundry aid or as a supplementary component of the laundry detergent itself. Numerous substances have been studied as dye transfer inhibitors. A number of these substances include polyvinyl pyrrolidone (U.S. Pat. No. 4,006,092), polyvinyl alcohol (CA 2,104,728), polyvinyl imidazole (DE 3,840,056), polyamine-N-oxides (EP 579,295), cationic starches (U.S. Pat. No. 4,756,849; EP 044003), minerals such as magnesium aluminate and hydrotalcite (U.S. Pat. No. 4,392,961; U.S. Pat. No. 4,661,282; U.S. Pat. No. 4,929,381; and U.S. Pat. No. 5,149,456), polyethylene imines (DE 3,124,210), polyvinyl oxazolidone (DE 2,814,329), enzymatic systems including peroxidases and oxidases (U.S. Pat. No. 5,273,896; U.S. Pat. No. 5,288,765), oxidants (U.S. Pat. No. 4,005,029; U.S. Pat. No. 4,123,376; U.S. Pat. No. 4,300,897; and U.S. Pat. No. 4,338,210), cationic and amphoteric surfactants (U.S. Pat. No. 4,239,659; and U.S. Pat. No. 4,261,869), as well as propylene oxide reaction products (U.S. Pat. No. 4,389,214).
One aspect of the present application relates to a dye scavenging article for the convenient control of fugitive extraneous dyes which may be present in the wash liquor, wherein the article adsorbs such dyes onto a support substrate in a novel way.
The present application also provides a visually perceivable image-forming dye scavenging article capable of absorbing and/or inhibiting transfer of extraneous fugitive dyes released during laundering.